In Belgium’s’ Antwerp Diamond District, eighty percent of the world’s rough diamonds passed through a three-square-block area. The Diamond Squad, the world’s only specialized diamond police, provided 24-hour police surveillance and 63 video cameras monitored the district. In this area, the Antwerp Diamond Center vault was thought to be impenetrable. In addition to having a 3-ton steel vault door, sensing played a key part in the 10 layers of security in the Antwerp Diamond Center vault. The layers in the protection strategy included:
1. Combination dial (0-99)
2. Keyed lock
3. Seismic sensor (built-in)
4. Locked steel grate
5. Magnetic sensor
6. External security camera
7. Keypad for disarming sensors
8. Light sensor
9. Internal security camera
10. Heat/motion sensor
Did it Work?
The Antwerp Diamond Center is now infamous for being the world’s greatest diamond heist. The question is: how did they do it? As noted in the History Channel’s “History Stories,” “The thieves disabled many of the vault’s security systems, such as heat and motion sensors, using common household goods such as hairspray, Styrofoam and tape.”
The criminals’ entry point was a terrace in a private garden – one of the few places in the district that wasn’t under video surveillance. A heat-sensing infrared detector monitored the terrace. However, when the sensor was approached slowly from behind with a large homemade polyester shield held by the criminal, the low thermal conductivity of the polyester blocked the criminal’s body heat from reaching the sensor. Once he placed the shield directly in front of the detector, it did not sense anything.
A custom-designed piece of aluminum with heavy-duty, double-sided tape on one side was attached to the two-piece magnetic field sensor on the vault door. This allowed the two pieces of the sensor to be unscrewed and moved out of the way in their armed state without setting off an alarm.
Security cameras were covered with black plastic bags before the lights were turned on.
The vault’s security system including the seismic alarm was bypassed by a small piece of wire placed between the inbound and outbound cables. Then the light sensor was covered with tape, taking it out of the protection scheme.
Finally, coating the combined heat/motion sensor in the vault with a thin coat of transparent, oily mist from a woman’s hairspray disabled it. The hairspray temporarily insulated the sensor from fluctuations in the room’s temperature and the alarm triggered only if it sensed both heat and motion.
From an engineering and systems design perspective, the important take away is that any security scheme can eventually be defeated. Designers may take weeks or even months to create a sensor or system designed to protect a vault, a home or a business. However, the determined thief or hacker can break-in – especially if the reward is great enough. For a legendary heist, the gang leader(s) can plan for years to execute the perfect heist. While they may not get away with it, the thieves often show designers the shortcomings of their design that were never taken into consideration because the designers did not think like criminals – real criminals.
Filed Under: Sensor Tips